#!/usr/bin/python3
mile = int(input("请输入里程"))
money = 13 
if mile<0:
    money = 0
    print("输入错误")
elif mile<=3:
    pass
elif mile<=15:
    money = 13 + (mile-3)*2.4
else:
    money = 13 + (mile-3)*2.4 + (mile-15)*1.2
print("你的车费：",money)
